ON CRUSTACEA. 
305 
upon this genus, a name by which the ancients designated a 
sort of crab, or one of the brachyurous Crustacea. The in- 
habitants of the maritime coasts of France, who are also ac- 
quainted with the habit which these animals have of enclosing 
themselves in univalve shells which they find empty, call 
them hermits , or soldiers , because they compare this shell, 
which serves them as a dwelling, to the cell of a hermit, or the 
sentry-box of a soldier. Linnaeus placed them in the genus 
cancer, but they have been ascertained strictly to belong to 
the macrourous decapods. 
Aristotle had already mentioned the fact, that the shell 
serving as an habitation to the carcinion, or pagurus, was not 
of its own formation ; that it had possessed itself of it after the 
death of the molluscous animal which had formed it; and that 
its body was not adherent to it, as is that of the last mentioned 
animal. Belon, Rondelct, and many other naturalists, had 
confirmed these facts ; Swammerdam has, nevertheless, pre- 
tended, contrary to so many and such well founded authori- 
ties, that the pagurus was born with its shell, and that it even 
possessed the faculty of enlarging it, in proportion to its own 
growth. It is positively known, that on its issuing from the 
egg, its body is naked or without a shell; that its form does 
not then essentially differ from that which it presents in the 
adult state ; and, finally, that it is without the mantle and the 
secretory organ, which nature has accorded to the mollusca for 
the formation of their shells. 
It has also been falsely advanced, that the pagurus puts to 
death the natural proprietor of the shell in which it is de- 
sirous of establishing itself. It only takes possession of one 
that is empty; and that the posterior extremity of its body 
may fasten there, it always selects one, the summit of which 
finishes in a spiral. It is but once a year, at the period 
of moulting, that, its body, having increased in bulk so as 
to be too much confined in its domicile, it is obliged to 
von. xirr. 
x 
